Pointing device for a portable computer

ABSTRACT

A pointing device according to the present invention includes a trackball embedded in the case of a computer display. The trackball is placed adjacent to the display and the select buttons for the trackball are located on the backside of the display case behind the trackball. The user guides the trackball with his thumb and pushes the select buttons on the backside of the case with his index and middle fingers, allowing the user to operate the pointing device with only one hand. Alternatively, the trackball is embedded in the corner of the keyboard of a desktop system, with the select buttons on the opposite side of the keyboard behind the trackball. With the keyboard standing on legs, the user&#39;s fingers can reach the two select buttons opposite the trackball to operating the pointing device.

This is a division of application Ser. No. 08/025,071 filed Mar. 2, 1993now abandoned which is a division of Ser. No. 885,121 filed May 18, 1992U.S. Pat. No. 5,208,736 issued May 4, 1993

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention generally relates to pointing devices used with computersystems, and more particularly, to a trackball for use with portablecomputers and capable of being embedded in portions of the computer.

2. Description of the Related Art

The tremendous growth of the computer industry in recent years has beenaccompanied by advances in both computer hardware and software.Computers have become more convenient to use and so affordable that manyindividuals now own personal computers. As computer systems havedeveloped to become more accessible to personal users, software has alsoevolved into complex programs that are simple for a relatively untraineduser to operate. To maximize user comfort and familiarity, much of thecurrent software is graphics oriented, using icons and pointers to allowthe user to choose a desired application.

Pointing devices provide a simple interface between users and graphicsoriented applications, allowing the user to indicate what he wants bymerely pointing to it on the display. A user can initiate a program bysimply moving the cursor to the desired option and pressing a selectbutton. As the program runs, it provides the user with more optionsrepresented on the display of the computer, and the user directs theexecution of the program using the pointing device.

For desktop computers, a mouse is the most common pointing device, as itis reliable and easy to use. A mouse is a device moved about a flatsurface while the cursor on the display follows the movement of themouse. In many mice a ball located on the bottom of the unit is incontact with the desktop or a mouse pad and rolls when the mouse ismoved. This rolling is converted into X and Y values and provided to thecomputer. In addition, mice have one, two or three buttons forindicating user selection. The buttons are typically located on the topside of the mouse.

Other pointing devices include trackballs, which are essentially micewith the ball and buttons facing upward; digitizing pads; forcesensitive keys; and touch screens. Most of these items are generally notintegral parts of the computer, but are made by other manufacturers tobe used in conjunction with the computer system. As a result, mostpointing devices comprise separate units apart from the computer system.

Consequently, a mouse or other common pointing device is notparticularly well suited to a portable computer. Powerful systems arenow available in portable units no larger than a thick notebook and canoperate in almost any environment. But for portable systems, such aslaptop and notebook computers, any extra equipment that has to becarried with the computer decreases the system's portability. Ideally,the user would only have to transport the computer itself. Aconventional mouse, however, is a relatively large device, employs along cord, requires a surface on which to roll, and is not an integratedpart of the computer. Other pointing devices share these and otherproblems.

The shortcomings of pointing devices in a portable system have usuallybeen addressed by using trackball devices. The device's size has beenreduced and the cable shortened to improve the devicets compatibilitywith a portable system. To use the device, it is usually attached to theside of the computer case next to the keyboard, and plugged into aconnector at the back of the computer during operation. The size ofthese devices has been reduced. Although these improvements are helpful,they only reduce the problems associated with a mouse or trackballwithout eliminating them. A smaller mouse with a shorter cord stillneeds a relatively wide, flat area to operate, and a trackball clampedto the side of the computer remains a hindrance that must be carriedwith the computer and generally disconnected for travel.

Several computer systems used embedded pointing devices. Computerkeyboards are available which use a miniature trackball mounted in onecorner, with the trackball and the buttons facing upwardly. Anotherkeyboard embedded pointing device is a small touch pad located at oneend of the keyboard. In its Powerbook series of laptop computers, AppleCorporation has mounted a trackball and two arc-shaped buttons below thespace bar on the keyboard. An alternative design used in some portablecomputers is the Isopoint (TM) unit. The Isopoint design is basically acylinder which rotates axially and slides longitudinally, the cylindermounted below the space bar. Buttons flank the cylinder or the entirecylinder can be depressed. In yet another variation, one manufacturer isproviding a "wobble key." One special key on the keyboard is designed sothat it not only can be depressed, but also can be moved or pivoted infour directions, thus providing X and Y movement. The Apple and Isopointdesigns have the problem of requiring increased space below thekeyboard, an area already highly cramped in notebook computers. Thewobble key requires a very complicated key and is not necessarily highlysensitive or intuitive. Conventional integrated designs also occupyrelatively large amounts of space because of the ball and buttons beingaccessible from only one side.

Thus the known pointing devices are either too large and cumbersome foruse if not integrated, require undesirably large amounts of space inintegrated designs or are simply not considered sufficiently accurateand usable.

SUMMARY OF THE INVENTION

A pointing device according to the present invention permits the user tooperate an intuitively simple pointing device comfortably, with thedevice being integrated with the computer and yet not enlarging the sizeof the computer. In the preferred embodiment, a trackball is embedded inthe housing of the display. The trackball is placed adjacent to thedisplay and facing the user, preferably near the lower right handcorner, and the select buttons for the pointing device are located onthe backside of the display housing behind the trackball. To use thepointing device, the user guides the trackball with his thumb and pushesthe select buttons on the backside of the housing with his index andmiddle fingers. In addition, because the user's hand is in a naturalposition as if it were lightly gripping the side of the display case, apointing device according to the present invention offers improvedaccuracy and simplicity to the user. Because the user's hand can rest onthe side of the base section, the placement of the pointing device inthe display part of the case further reduces the discomfort and fatiguesuffered by the user. In addition, with the trackball closer to thedisplay and oriented in the same plane as the cursor, movement of thetrackball correlates more intuitively to the movement of the cursor.Locating the trackball in the display section of the computer furthereliminates the need to make room for the pointing device in the alreadycrowded base section of a laptop or notebook computer. Unlike a separatemouse or trackball, the embedded pointing device also eliminates theextra piece of hardware to be carried with the computer and requires nospace for manipulation.

In an alternative embodiment, a trackball is embedded in the keyboardsection of a desktop system. Preferably, the trackball is embedded inthe top side and upper right hand corner of the keyboard, with theselect buttons on the opposite or bottom side of the keyboard behind thetrackball. With the keyboard standing on its legs, the user's fingerscan reach the two select buttons opposite the trackball to operate thepointing device. Like the portable computer embodiment, this designimproves user comfort and maximizes the useability of the pointingdevice.

BRIEF DESCRIPTION OF THE DRAWINGS

A better understanding of the invention can be obtained when thedescription of the preferred embodiment is considered in conjunctionwith the following drawings, in which:

FIG. 1 is a perspective view of a notebook computer incorporating thepresent invention;

FIG. 2 is a side view of the computer of FIG. 1;

FIG. 3 is a partial front view in partial cutaway of the notebookcomputer of FIG. 1;

FIG. 4 is a partial side view of the computer of FIG. 3 showing theposition of two select buttons, hidden from view, on the backside of thedisplay case taken along the line 4--4;

FIG. 5 is a partial front view of the notebook computer of FIG. 1;

FIG. 6 is a view in partial cross section of the trackball and buttonsof the notebook computer of FIG. 5, taken along the line 6--6;

FIG. 7 is an exploded view of a trackball pointing device having twoselect buttons mounted on the underside of the circuit board;

FIG. 8 is a perspective view of a notebook computer similar to that ofFIG. 1, but having the pointing device located to the left of thedisplay;

FIG. 9 is a perspective view of a desktop computer and keyboardincorporating the present invention; and

FIG. 10 is a side view in partial cutaway of the keyboard shown in FIG.9.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring now to FIGS. 1 and 2, a portable computer system C, like anotebook or laptop computer incorporating the present invention isshown. The portable computer C includes all of the capabilities andfeatures of a desktop unit. Portable computers, however, are relativelylight and compact, and can operate using rechargeable batteries. Theportable computer C generally comprises two sections which are hingedtogether on one side. A base section 10 includes a keyboard 12 and mostof the computer system components and the power supply circuitry,including the rechargeable batteries. Floppy and fixed disk drives andperipheral ports are also located in the base section 10. The topsection 14, on the other hand, includes a generallyparallelepiped-shaped housing 18 which contains a display 16 visiblethrough an opening in the housing 18 and display control circuitry.Because the display 16 is generally a liquid crystal display (LCD),backlighting is required to provide a contrasting background for thedarker images on the display 16. Thus, the top section 14 also includesbacklighting circuitry to generate light behind the display 16. Thedisplay 16 and the other components are encased in a rigid plastichousing 18 joined to the base section 10 of the computer C. The computerC opens so that the display 16 stands generally upright while the basesection 10 rests flat on a surface.

The top section 14 further includes a trackball 20 embedded in thehousing 18 of the top section 14. Moving the trackball 20 causes thecursor to move about the display in the same direction as thetrackball's motion and at a proportional speed. A shallow recess 22 isformed in the front of the housing 18 near the display 16, and thetrackball 20 is placed in the deepest part of the recess 22. The recess22 is deep enough to prevent the trackball 20 from protruding beyond theplane of the display 16, allowing the computer C to fold togetherwithout hindrance from the trackball 20. Optimally, the trackball 20 isthe width of an ordinary hand from the bottom of the display housing 18and the length of an ordinary thumb from the side. At this location, thetrackball 20 is positioned where the ordinary user's thumb wouldnaturally be with his hand resting on the base section 10 and wrappedaround the top section 14. The trackball 20, described in further detailbelow, rolls relatively freely within a socket 36 (FIG. 7) behind therecess 22, and is held in the socket by a retaining ring 40.

Referring now to FIGS. 3 and 4, the portable computer C further includestwo select buttons 24, 26 for designating particular points on thedisplay and providing various other information to the system, generallyduplicating the buttons found on two button mice. The exact function ofthe select buttons 24, 26 depends upon the program being executed. Theselect buttons 24, 26 are placed on the backside of the display housing18, opposite the display 16, and one select button 26 is locateddirectly behind the trackball 20. Thus, the trackball 20 is positionedso that the user's thumb can rest on the trackball 20, while his handwraps around the outside of the display housing 18 and his index andmiddle fingers rest on the two select buttons 24, 26, respectively. Toprevent damage to the buttons 24, 26 during transport and for aestheticpurposes, the buttons 24, 26 are mounted so that their outside surfacesare flush with or recessed below the outside of the top section 14.

It should also be noted that the trackball 20 and the select buttons 24,26 can be located anywhere along the outside of the display housing 18.The top section 14 generally includes, however, display backlightingcircuitry 27 which generates significant electromagnetic noise which canadversely affect the operation of an unshielded pointing device.Consequently, the pointing device and its connecting wires must beelectromagnetically shielded to prevent interference.

Referring to FIG. 6, a top view similar to FIG. 4 is provided. Thetrackball 20 is shown to be not centered between the display 16 and theedge of the top section 14 but is located closer to the edge of the topsection 14.

Referring now to FIG. 7, a trackball pointing device D of the preferredembodiment is shown having two select buttons 30, 32 mounted opposite atrackball 20. The trackball 20 can be rolled in any direction and thecursor moves correspondingly on the display. In the preferredembodiment, the pointing device D employs an optical trackball, asopposed to a mechanical trackball. The pointing device includes thetrackball 20 mounted within a socket 36 formed in a receiving plate 38,and is held in place by a retaining ring 40 which is held over the topof the trackball 20 and attached to the socket to prevent the trackball20 from falling out of the socket 36. Preferably, the trackball 20 iseleven millimeters in diameter, suitable for movement by the user'sthumb. Inside the socket 36, the receiving plate 38 includes fourrollers (not shown) on which the trackball 20 rests. When the trackball20 is moved, the rollers rotate. The ends of two of the rollers areparts of separate optical systems to determine how fast and how far thetrackball 20 rolls on each roller. From this information, the verticaland horizontal direction and speed of the cursor's intended movement canbe determined and provided to the graphics software.

The receiving plate 38 for the trackball 20 is attached to a circuitboard 42. The circuit board 42 includes all of the circuitry required todetect movement of the rollers caused by the trackball 20 and providethe data to the pointing device input of the computer C. On the oppositeside of the circuit board 42, the select buttons 30, 32 are positionedwithin switches 44, 46 attached to the underside of the circuit board42. Each switch 44, 46 is connected to the circuitry mounted on thecircuit board 42 to allow the user to designate specific cursorlocations on the display and interact with the system. The select button30 is received by a mating location in select button 26, while selectbutton 32 is received by a mating location in select button 24. Thusdepressing select button 26 activates switch 44 and depressing selectbutton 24 activates switch 46.

The preferred embodiment can easily be adapted to suit a left-handeduser. As shown in FIG. 8, the portable computer C can simply be designedwith the trackball 20 in the lower left corner, with the select buttons24, 26 located directly behind it. In an alternative embodiment, thepointing device is a removable module that can be placed, at the user'schoice, on either the left side or the right side of the displayhousing. To change the system, a left-handed user removes a panel fromthe left side of the display case, disengages the pointing device fromits position on the right side of the display housing, and exchanges thepositions of the two pieces. The system is designed to respond to thetrackball 20 in either location.

Placing the trackball 20 near the display 16 offers several advantages.For graphics oriented software, easy and natural use of the pointingdevice is an important feature of the computer C. On the other hand,although a mouse is simple and easy to use, it is a nuisance andimpractical for portable computers. Embedding the trackball 20 in thetop section 14 provides a practical substitute for a mouse without aseparate piece of hardware or the need for extra space. In addition, thetrackball 20 is oriented in the same plane as the plane in which thecursor moves, so that movement of the trackball 20 in a particulardirection in relation to the top section 14 moves the cursor in exactlythe same direction. Consequently, movement of the trackball 20correlates more intuitively to the movement of the cursor. The locationof the select buttons 24, 26 behind the trackball 20 allow the user tooperate the pointing device with one hand and minimum effort, reducingdiscomfort and fatigue.

In an alternative embodiment, the embedded trackball may be adapted to adesktop system. Referring now to FIGS. 9 and 10, a trackball 50 isembedded in the upper right-hand corner of a computer's keyboard 52.Similar to the first embodiment, select buttons 54, 56 are placed on theunderside of the keyboard 52 directly behind the trackball 50. The useroperates the select buttons 54, 56 by reaching under the keyboard 52with his index and middle fingers and placing his thumb on the trackball50. The select buttons 54, 56 are more accessible using a conventionalpair of legs 58 on the underside of the keyboard 52 for propping thekeyboard 52 towards the user. As in the preferred embodiment, thetrackball 50 can be placed on either the left side or the right side ofthe keyboard 52, depending upon the user's preference.

For desktop systems, embedding the trackball 50 in the keyboard 52offers many of the same advantages as in the portable version. With thetrackball 50 on the keyboard section, all of the user input interfacedevices are located near the keyboard 52. A separate mouse unit, whichrequires space and adds to the clutter of equipment, is no longernecessary for graphics oriented applications.

The above disclosure and description of the invention are illustrativeand explanatory thereof, and various changes in size, shape, materials,components, circuit elements, wiring connections and contacts, as wellas in the details of the illustrated circuitry and construction, may bemade without departing from the spirit of the invention.

We claim:
 1. A portable computer system comprising:a base section; and adisplay section pivotably connected to said base section, said displaysection including: a housing, said housing being generally aparallelepiped and including a front face, a back face, a bottom face,two side faces and a first opening in said front face, said firstopening being less than the size of said front face so that a borderresults, a second opening in said border and a third opening in saidback face; a display for displaying an image, said display locatedinside said housing at said first opening; and a user interface devicelocated inside said housing, said user interface device including:apointing device projecting through said second opening; and a firstselect button located near said pointing device and projecting throughsaid third opening.
 2. The portable computer system of claim 1, whereinsaid housing further includes a recess formed around said secondopening.
 3. The portable computer of claim 1, wherein said housingincludes a fourth opening in said back face, said fourth opening locatednear said third opening, and wherein said user interface device furtherincludes a second select button projecting through said fourth opening.4. A computer system including a base section pivotably connected to adisplay section, comprising:a housing for one of said sections having afront face, a back face, side faces and a first opening in said frontface, and a second opening in said back face; and a user interfacedevice located within said housing, said user interface deviceincluding:a pointing device positioned in said first opening; and afirst select button positioned in said second opening.
 5. System ofclaim 4, wherein said housing includes a third opening in said backface, said third opening located near said second opening, and whereinsaid user interface device further includes a second select buttonprojecting through said third opening.
 6. System of claim 4 wherein saidhousing is in said display section.
 7. A computer system having a basesection pivotably connected to a display section comprising:a housingfor one of the computer system sections having a front and a back; and auser interface device embedded in said housing, said user interfacedevice including:a pointing device positioned in the front of saidhousing; and a select button positioned in the back of said housing. 8.System of claim 7 wherein said pointing device is a trackball.
 9. Systemof claim 7 wherein said housing further includes a recess formed aroundsaid pointing device.
 10. System of claim 8 wherein said housing furtherincludes a recess formed around said pointing device.
 11. System ofclaim 7 wherein said housing includes a second select button positionedadjacent said first select button.
 12. System of claim 11 wherein saidsecond select button is positioned on the back of the housing. 13.System of claim 7 wherein said housing is in said display section.